comparative evaluation of stability of two different...

COMPARATIVE EVALUATION OF STABILITY

OF TWO DIFFERENT FORMS OF IMMEDIATELY LOADED

IMPLANTS SUPPORTING A FIXED FULL ARCH PROSTHESIS.

AN IN-VIVO STUDY

Dissertation Submitted to

THE TAMILNADU Dr. M.G.R. MEDICAL UNIVERSITY

In partial fulfillment for the Degree of

MASTER OF DENTAL SURGERY

BRANCH I

PROSTHODONTICS AND CROWN & BRIDGE

APRIL 2016

CERTIFICATE

This is to certify that this dissertation entitled “COMPARATIVE EVALUATION

OF STABILITY OF TWO DIFFERENT FORMS OF IMMEDIATELY LOADED

IMPLANTS SUPPORTING A FIXED FULL ARCH PROSTHESIS - AN IN-VIVO

STUDY” is a bonafide research work done by Dr. P.KAMALASHANKAR under our

guidance and to our satisfaction during his post graduate study period between 2013 – 2016.

This dissertation is submitted to THE TAMILNADU Dr. M.G.R. MEDICAL

UNIVERSITY, in partial fulfillment for the Degree of MASTER OF DENTAL

SURGERY in PROSTHODONTICS AND CROWN & BRIDGE - BRANCH I. It has

not been submitted partially or fully for the award of any other degree or diploma.

Head Of The Department Guide

Dr.T.J.Suneetha MDS. Dr. S. Sabarinathan, MDS Professor and HOD Reader Department of Prosthodontics and Department of Prosthodontics and Crown & Bridge Crown & Bridge, Rajas Dental College & Hospital, Rajas Dental College & Hospital,

Tirunelveli. Tirunelveli.

ENDORSEMENT BY PRINCIPAL /

HEAD OF THE INSTITUTION

This is to certify that this dissertation entitled “COMPARATIVE EVALUATION

OF STABILITY OF TWO DIFFERENT FORMS OF IMMEDIATELY LOADED

IMPLANTS SUPPORTING A FIXED FULL ARCH PROSTHESIS - AN IN-VIVO

STUDY” is a bonafide research work done by Dr.P.Kamalashankar under the guidance of

Dr.S.Sabarinathan,M.D.S., Reader, Department of Prosthodontics and Crown and Bridge,

Rajas Dental College and Hospital, Kavalkinaru, Tirunelveli-627105.

Date : Dr. MARY KUTTY JOSEPH, M.D.S.,

Place : Kavalkinaru Principal,

Rajas Dental College& Hospital,

Kavalkinaru Jn,

Tirunelveli Dist.

ACKNOWLEDGEMENT

This dissertation is the result of work with immense support from many people and it

is a pleasure now that I have the opportunity to express my gratitude to all of them.

I would be failing in my duty if I do not adequately convey my heartfelt gratitude and

my sincere thanks to my Head of the Department, Professor Dr. T.J.Suneetha, M.D.S.,

Department of Prosthodontics and Crown & Bridge, for her exceptional guidance,

tremendous encouragement, well-timed suggestions and heartfelt support throughout my

postgraduate programme, which has never failed to drive the best out of me. I would like to

profoundly thank her for giving an ultimate sculpt to this study. I will remember her help for

life.

I would like to express my real sense of respect, gratitude and thanks to my Guide,

Dr. S.Sabarinathan M.D.S., Reader, for his guidance, constant support, back up and

valuable criticism extended to me during the period of my study. The timely help and

encouragement rendered by him has been enormously helpful throughout the period of my

postgraduate study.His special care in guiding this study is highly inspirational.

I would like to solemnly thank Dr. M.Aarti, M.D.S.,Dr Indumathi M.D.S Reader for

her valuable guidance and encouragement rendered by her. This dissertation has been the

fertile outcome of their massive endurance, support, proficient guidance and counsel.

I would also like to thank Dr.S.I.Joephin Soundar, Dr.Ramesh raja, Dr.Sajna senior

lecturers for their valuable suggestions and timely help given throughout my study.

It is my extreme pleasure to extend my gratitude to my beloved Chairman Dr.Jacob

Raja for his valuable support and constant encouragement throughout the period of my

study.

It gives me immense pleasure to convey my deep indebtness to our respected

Principal Dr. Mary kutty Joseph, Vice Principal (Academics) Dr.Cynthia Sathiasekhar,

Vice Principal (Administration) Dr.Johnson Raja, Director of Administration Dr.I.Packiaraj

and Members of the Ethical Committee and Review Board for the permission, help and

guidance throughout the course.

I thank Dr.MATHEW, M.D.S., for helping me with the statistical analysis of this

study.

I am grateful to my colleague, Dr.Vijay K for his patient endurance, co-operation and

whole hearted support he offered me during my postgraduate course. I extend my sincere

thanks to my senior colleagues Dr.Anbu Ila , Dr Shinemanoj , Dr.Aneesh.S, Dr.Jean

Mathew and my junior colleagues Dr. Arul Joshy.A, Dr.Mani Bernard.H, Dr selvin, Dr

shyma for their kind help and support.

Last but not the least, even though words wouldn't do much justice. I would like to

specially thank my parents Mr.S.Palaneeswaran & Mrs.P.Banumathy, my wife

Dr.Vijayabharathi ,my mentors Dr.K.Subramanian MBBS, Dr.T.Asirvatham manoharan

MBBS, Late Mrs.S.Sankara Subbulakshmi for their blessings and unconditional love.

Above all I thank GOD almighty for all the grace endowed upon me.

Place : Kavalkinaru Name : Dr.P Kamalashankar

Date : Signature:

CONTENTS

S.NO TITLE PAGE NO.

1. INTRODUCTION 01

2. AIM AND OBJECTIVES 06

3. REVIEW OF LITERATURE 08

4 MATERIALS AND METHODS 19

5. RESULTS 38

6. DISCUSSION 53

7. SUMMARY 62

8. CONCLUSION 63

9. BIBLIOGRAPHY 65

List of tables

Table no Title Page no

1. Randomisation schedule for implant placement 24

2. Intra oral sites and corresponding implant dimensions 31

3. Insertion torque values (ITV ) in NCm 39

4. Insertion torque values (ITV ) in NCm for Al oxide blasted / acid 39

etched surface

5. Insertion torque values (ITV ) in NCm for Resorbable blast 40

medium treated surface

6. Insertion torque Values and corresponding Scores 41

7. Comparison of Insertion torque values (ITV ) of Al Oxide blasted

acid etched surface (Group A) and Resorbable blast medium 41

(RBM) treated (GroupB) implants

8. Site specific Implant Stability Quotient (ISQ) values 42

9. Implant Stability Quotient (ISQ) values for Al oxide blasted / acid

etched surface (group A) 44

10. Implant Stability Quotient (ISQ) values for Resorbable blast 44

medium treated surface (group B)

11. Comparison of mean implant stability quotient (ISQ) values of Al

Oxide blasted / acid etched surface (Group A) at different time 45

intervals

12. Post hoc comparison of implant stability quotient (ISQ) of Al

Oxide blasted / acid etched surface (Group A) at different time 46

intervals

13. Comparison of mean implant stability quotient (ISQ) values of 47

Resorbable blast medium (RBM) treated surface (Group B) at

different time intervals

14. Post hoc comparison of implant stability quotient (ISQ) of 48

Resorbable blast medium (RBM) treated surface (Group B) at

different time intervals

15. Comparison of implant stability quotients (ISQ) of Al Oxide 49

blasted / acid etched surface (Group A) and Resorbable blast

medium (RBM) treated surface (Group B) implants at different

time intervals.

List of graphs

Graph no Title Page no

1. Mean ISQ values of Al Oxide blasted / acid etched surface (Group A) 50

2. Change in ISQ over 1 year period for Al Oxide blasted / acid

etched surface (Group A) 50

3. Mean ISQ values of Resorbable blast medium (RBM) treated

surface (Group B) 51

4. Change in ISQ over 1 year period for Resorbable blast medium

(RBM) treated surface (Group B) 51

5. Comparison of ISQ values of Al Oxide blasted / acid etched surface

(Group A) and Resorbable blast medium (RBM) treated surface 52

(Group B) implants at different time intervals.

List of figures

Fig :1 Completely Edentulous Maxillary & Mandibular Arch

Fig :2 Maxillary Arch.

Fig :3 Mandibular Arch.

Fig 4 Pre-op OPG.

Fig 5 Face bow Transfer. ( frontal view)

Fig 6 Face bow Transfer.( lateral view)

Fig 7 Complete denture rehabilitation done in relation to maxillary and

mandibular arch.

Fig 8 Clear Acrylic Duplicated lower denture with radio-opaque

markers.

Fig 9 pre-op CBCT evaluation. A, paraxial sections with markers. B,

Panaromic sections with markers.

Fig 10 Radiographic stent fabrication done.

Fig 11 Accuracy of Radiographic stent evaluation and angulation

conformation by check CBCT. A .panaromic view. B . paraxial

view.

Fig 12 ARMAMENTARIUM.

a, Surgical Instruments.

b, Physiodispenser

c, Implants to be used - blinded for six different sites

Fig 13 Muco periosteal flap elevated.

Fig 14 Pilot drill (2 mm ) placed through the stent.

Fig 15 Implant placed in site VI, paralleling pins placed in site IV and V

Fig 16 Insertion torque value evaluated with caliberated Torque wrench.

Fig 17 RFA checked in the site VI after the placement of implant.

Fig 18 Healing collar placed.

Fig 19 OSTELL Mentor device.

Fig 20 Implants placed at the bone level- Healing collar placed.

Fig 21 Suturing done with BSS.

Fig 22 Immediate Post OP –OPG with healing collars placed.

Fig 23 Open tray transfer done.

Fig 24 OPG to check the seating of the open tray transfer.

Fig 25 Impression making with custom tray A, Frontal view B, Occlusal

view.

Fig 26 PENTAMIX -2 machine.

Fig 27 Impression made with –Monophase( poly ether).

Fig 28 Pick up impression- tissue surface.

Fig 29 1 week post op healing.

Fig 30 Working cast.

Fig 31 Hybrid screw retained mandibular prosthesis with opposing

maxillary complete denture.

Fig 32 1 week healing of soft tissue.

Fig 33 Hybrid Prosthesis placed in the lower jaw .

Fig 34 occlusion of the lower hybrid prosthesis with maxillary complete

denture.

Fig 35 TDS – milling machine a,b,c.

Fig 36 TITANIUM blank milling process a,b,c,d,e,f,g.

Fig 37 Titanium milled bar ( screw retained)

Fig 38 Immediate Post op OPG after placement of the Hybrid prosthesis.

Fig 39 a ,1 month post op .b, intra oral view. C , intra oral lateral view.

Fig 40 1 month post op healing.

Fig 41 RFA taken a. mesial value .b, buccal value .

Fig 42 1 month post op.



Fig 45 1year post op.

Fig 46 case 2 .

Fig 47 case 3 .

Fig 48 Case 4 .

Fig 49 Case 5.

Introduction

INTRODUCTION

1

Partial or complete edentulism is a major oral health concern in a

large part of the adult population and there is a need for treating a sizeable percentage of such

population with prosthodontic rehabilitation. Traditional treatments comprising of removable

prostheses are often inadequate in restoring full masticatory function and can negatively affect

nutrition, physical appearance and self-esteem.14,31Osseointegrated dental implants offer

effective and definitive solutions for such scenario. Dental Implants have become a milestone in

dentistry and have changed the face of dentistry over the last three decades. Numerous

alternative oral therapies and definitive rehabilitation procedures that could not be done with

conventional techniques have been realised with the advent of osseointegrated implants. A large

body of sound scientific research and decades of clinical use have verified and validated their

usefulness in replacing missing teeth.16,28,31 Clinical evidence has shown excellent long term

results for osseointegrated implants with success rates above 90%.11,14

Dental implants were first introduced for people who were

completely edentulous and who had great difficulty stabilizing or tolerating dentures, largely

because of the atrophy of the alveolar bone and mucoperiosteum upon which the dentures rest.

The main objective in the treatment of completely edentulous patients with osseointegrated

implants is either to avoid removable complete dentures by placement of complete implant-

supported fixed prosthesis or to improve retention and stability of removable complete dentures.

It was well known even then that osseointegration is best in dense bone, generally in the front

part of the lower jaw. It is interesting to note that the use of implants in prosthodontics was

restricted to the treatment of completely edentulous mandible with a fixed prosthesis in the

INTRODUCTION

2

earlier days. Also, the submerged protocol , two stage surgery and delayed loading were much in

vogue as proposed by authors like Branemark and Alberktsson et al.14

Today implants are used to replace either single or multiple

missing teeth apart from treating completely edentulous situations. Implants are infact proposed

as the first line of treatment for many conditions which earlier were treated with either

removable or fixed, tooth or tissue supported prostheses. Innovations in the design , geometry

and surface characteristics of dental implants were essentially introduced to widen the scope of

implant therapy to a wide range of clinical situations such as complete edentulism , long and

short span partial edentulism , missing single tooth, maxillofacial prosthetics, etc.

Advancements in the material science, imaging systems and prosthetic technology has also led to

a phenomenal change in the way implant treatment planning and execution is carried out.

The successful outcome of any implant procedure needs a series of

patient related factors (bone volume and density) and procedure dependent parameters (type of

implant and surgical procedure) to be considered . Modern implants come in a variety of shapes

and sizes to suit the different edentulous situations they replace and also according to the types

of prosthetic teeth or superstructure to be supported by the implants. Their surfaces have been

improved to enhance the osseointegration process. Instead of being smooth or machined, they are

generally roughened by different manufacturing techniques which dramatically increase the

surface area to which bone can attach.22,26,41

The successful integration of any implant is dependent on the

primary stability of the implant achieved during placement and is more so with immediately

loaded implants.5,6 Primary stability is dependent on bone quality, implant design and surgical

technique. Surgical techniques to improve bone quality and enhance bone density during implant

INTRODUCTION

3

placement have been developed. Similarly , new implant designs have been proposed to achieve

high stability even in poor quality bone. A combination of macro thread design to achieve high

initial stability and micro roughened surface to improve bone implant contact is employed in

the majority of the commercially available implants today. Modification of screw threads has

been shown to increase the pullout strength of implants and influenced the insertion torque

values26,41. New implant biomaterials are developed aiming to alter cellular performance at the

bone – implant interface. Research has provided strong evidence supporting improved

osseointegration , increased bone – implant contact (BIC) , increased mechanical stability and

improved soft tissue health with surface treated implants. Schroeder et al observed that a rough

and porous surface increases the effective surface about 12 times in relation to a smooth one

generating an osteo – inductive effect and increasing the anchoring of the implant in bone.44

Surface texturization can be achieved through a variety of

processes namely, acid etching, sand blating and associating acid treatment and particle jetting

together. Also , many bioactive coated implants were proposed aiming to modify the host

response at cellular level and achieve better bone integration. These include hydroxyapatite ,

calcium hydroxide and bisphosphonate coated implant surfaces. Recently , titanium plasma

sprayed (TPS) and Resorbable blast media (RBM) treated implants are available. There were

some inherent disadvantages such as incorporation of oxide particles on the implant surface , loss

of coating during torquing of implants and inability to achieve homogenous roughness ,etc, with

such surface treated implants. The use of low intensity laser radiation for surface treatment of

implants has advantages like low contamination with chemicals and hence improved cell

metabolic and functional activities.33,44

INTRODUCTION

4

Attempts to decrease the treatment time with implant therapy have

also been made by many authors.30,36,43 Premature loading was considered detrimental to direct

bone apposition on the implant surface and was thought to result in fibrous encapsulation. While

the initial concept of submerged protocol and delayed loading was based on earlier concepts of

osseointegration, continued research has led to an improved understanding of bone biology ,

osseointegration and host response for immediate and early loading protocols. Immediate loading

is no longer considered to be risky and new clinical protocols with shortened healing periods or

immediate loading have been proposed with clinical success rates comparable to the original

protocol. More recent studies have illustrated that early loading of implants at a low magnitude

of force may aid in early peri-implant osteogenesis.37,43As mentioned earlier , the main

requirement to allow immediate loading of dental implant is its primary stability when inserted

into the osteotomy site. The micromotion of the implant during loading in its early stages should

be below 150 µm , above which fibrous encapsulation may occur40.

In addition to the above factors, splinting of multiple implants is

also expected to reduce the implant micromotion during healing stage. Immediate prosthetic

loading of the implants , either functional or nonfuntional is indicated as part of treatment

protocol by many clinicians. The All –on – four technique proposed by Paulo malo is one such

protocol with reported success of more than 95%36. Immediate loading of either axially placed or

tilted implants in completely edentulous jaws has now become a norm rather than exception.

Studies regarding the various factors affecting primary stability

and immediate loading such as bone quality, surgical techniques and implant design and surface

characteristics are available in the literature. However, many of them are either in vitro studies

INTRODUCTION

5

done in artificial bone or cross sectional studies. While the initial mechanical stability of

implants can be roughly assessed with synthetic and cadaveric bone models, the influence at

cellular level due to the surface characteristics are best researched in an in vivo model which

includes animal studies followed by histomorphometric analysis and human clinical trials.

Long term , Prospective human clinical trials are considered to be

the gold standard in evidence based dentistry , the results of which can be extrapolated to clinical

practice with more accuracy and confidence. Such clinical trials are comparatively few

regarding the influence of surface treatments of implants on the primary and long term stability

of implants.

Hence this clinical study was undertaken to evaluate the influence

of two different surface treatments on the primary and long term clinical stability of endosteal

implants supporting an immediately loaded full arch fixed prosthesis.

Aim and Objectives

of the Study

AIM AND OBJECTIVES

6

AIM:

The aim of this study was to determine the difference in the primary and progressive clinical

stability if any, between two types of root form endosseous implants with two distinct implant

surfaces namely Acid etched surface/ Al Oxide blasted surface and Restorable blast medium

(RBM) treated surface when loaded immediately with a full arch fixed prosthesis.

OBJECTIVES:

To measure the stability of the above mentioned groups of implants immediately after

insertion (Primary stability).

To measure the stability of the above mentioned groups of implants 1 month after

insertion of definitive prosthesis.

To measure the stability of the above mentioned groups of implants 3 months after






To compare the difference in stability among the Al Oxide blasted / acid etched surface

implants at different time intervals (at the time of insertion, 1 month, 3 months, 6 months

& 12 months after insertion).

To compare the difference in stability among the Restorable blast medium (RBM)

(Calcium phosphate) treated surface implants at different time intervals (at the time of

insertion , 1 month, 3 months, 6 months & 12 months after insertion).

AIM AND OBJECTIVES

7

To compare the difference in stability between the above mentioned two different surface

treated implants at different time intervals (at the time of insertion, 1 month, 3 months, 6

months & 12 months after insertion).

Review of

Literature

REVIEW OF LITERATURE

8

Branemark Pl, Zarb GA, Albrektsson T et al (1985)14 In the last three

decades, implant dentistry has emerged as a fully accepted discipline in dentistry. During this

period of development, its concepts and treatment modalities have undergone tremendous

changes. At first, only protocols involving two-stage surgery were recognized as providing

reproducible and reliable results .

Antezak-Bouckoms AA, Tulloch JF, Berkey CS (1990)4 Several types of

research designs are available including, split-mouth design, whole-mouth design, and cross-over

clinical trials. The split-mouth design is a popular design in oral health research. In the most

common split-mouth study, each of two treatments are randomly assigned to either the right or

left halves of the dentition. The attractiveness of the design is that it removes a lot of inter-

individual variability from the estimates of the treatment effect. Split-mouth design seems to be

an effective type of clinical trial giving the advantages of reducing bias, obtaining definitive

results, and decreasing cost.

Buser D, Weber HP, Bragger U, Balsiger C. et al(1991) 15Proposed a single-

stage surgical procedure that became acceptable.

Meredith N, Alleyne D, Cawley P. et al(1996)34 proposed a Quantitative

determination of the stability of the implant-tissue interface using resonance frequency analysis.


9

Meredith N, Book K, Friberg B, Jemt T, Sennerby L. et al(1997)35 proposed a

cross-sectional and longitudinal study of resonance frequency measurements on implants in the

edentulous and partially dentate maxilla.

RFA is a test to assess implant stability by measuring the frequency of implant oscillation inside

the bone. A transducer connected to the implant is excited by means of an electric or magnetic

impulse (depending on the type of transducer used). Thus, the implant is subjected to slight

lateral force that causes lateral displacement due to elastic deformation of the bone. The

frequency of the registered oscillation depends on the stiffness of bone-implant attachment: the

stiffer the system is, the higher the transducer’s oscillation frequency will be.

There are several generations of transducers and assessment instruments. Recent generation

instruments (Osstell®; Osstell AB, Gothenburg, Sweden) need no computer to complete

analysis, are light, small, quick and easy to use in everyday clinic activity. Unlike previous

generations, the transducer demands no calibration in 3G instruments.

Stability values are expressed in ISQ (Implant Stability Quotient) units, which range from 1 (low

stability) to 100 (high stability). There is a specific transducer for each type of implant and the

obtained values do not depend on the type of transducer (44).

To compare different measurements taken with the same instrument, it must be capable of

reproducing highly similar values in different takes (i.e., the instrument is required to render a

high degree of repeatability). Besides, the values registered by means of different Smart-Pegs

must also be similar (i.e., the instrument is required a high degree of reproducibility).


10

Szmukler-moncler s ,salama H,reingewirtz Y et al(1998) 43Opinions vary

about the maximal acceptable interval between implant placement and loading. Some researchers

use the term immediate loading only when the provisional prosthesis is placed during the same

session in which surgery is performed .The delay most often observed for orderly placement of

prosthesis directly after the surgical procedure ranges between several hours and 5 days. It would

be tempting to use this practical framework in the definition of immediate loading. However,

many studies have documented results of treatment that followed an arbitrarily determined delay

of 48 to 72 hours. Furthermore, according to numerous authors, patients appear to be

increasingly interested in reduced treatment time between tooth removal and delivery of the final

implant-supported prosthesis, provided the level of predictability established during the previous

two decades is maintained.

Misch et al(1998)16 study has concluded that most of the immediate loaded

implants are placed in anatomical sites with dense and good bone quality. The mandible has a

better bone quality compared to the maxilla and this is the reason why reports are available

regarding immediate loading in mandible than maxilla.

Comparatively, related number of studies has concluded the concept of immediate loading in the

mandible for full arch restoration with the survival rates of 80-100% (31-33). Most of the studies

published on immediate loading in the mandible have considered mainly in edentulous patients.

Van Steebergh et al (2000)45 compared two implant systems with different

surface characteristics in a split mouth randomized design and came into conclusion that no

significant differences came out in concerned with probing depth or presence of plaque or


11

change in marginal bone level but statistically significant difference in location of marginal bone

level in relation to shoulder of the implant was found in favor of self tapping TiO 2 – blasted

screw shaped implants made of pure titanium in comparison with self tapping mark two implants

machine surface irregularities.

Szmukler-Moncler S, Piattelli A, Favero GA, Dubruille JH et al(2000)42

considered the application of early and immediate loading protocols in dental implantology

where the waiting periods for bone healing is shortened; instead of 3 to 8 months, no more than 6

to 8 weeks was deemed necessary.

Aparicio C, Rangert B, Sennerby L., et al(2002)5 Immediate/early loading of

dental implants they believe that, to qualify as an immediately loaded implant, the definitive

prosthesis must be placed on the same day .

Marjorie.k.jeffcoat et al (2003)33 Proposed a study to compare the efficacy of

the HA coated cylindrical Implant , HA coated threaded endosseous implant with that of

machined threaded endosseous implant as control &all were placed as two stage procedure. The

criteria of assessment was marginal bone loss not less than 2mm during 5years post loading

period from base line measurement .There were no significant differences in PI ,GI probing

pocket depth or gingival recession b/w groups at base line . He came in to conclusion that HA

coated cylinders had the highest success rate after restoration -99% followed by HA coated

threaded implants(97.9%) &titanium threaded implants-95.2%


12

Romanos et al,(2003)37 quoted that implant stability in the immediate loading is

seems to be increased due to the significant increase of the peri-implant bone density at the

implant-bone interface.

Vidyasagar(2004)46 stated that dental implant designs are influenced by overall

surface area, length and thread configuration. This can gain initial stability that would reduce the

threshold for the tolerated micro motion and minimize the waiting period. The design factors

incorporated into the dental implants would decrease the shear forces on the interface. The

design features may stimulate the bone formation and in which promotes bone healing and better

load distribution . There are different types of dental implants used in dentistry.

Alexandre-Amir Aalam, etal (2005).1 Clinical and radiographic comparison of

dental implants with surface roughened by anodic oxidation(tiUnite) dual etched implants

(osseotite) and machined implants and concluded that tiUnite, osseotite, and machined implants

had similar short term clinical outcomes.

Wilmes et al(2006) 48evaluated the initial stability of implant, which implies on

the bone quality and the surgical technique. The primary stability could be increased with the

bone quality, which would improve the osseointegration and increase the survival probability of

the dental implant. Even some studies have indicated the failure rate of dental implants is high in

poor-quality bone (22), and that the bone quality is higher for the mandible than for the maxilla.

In addition, the survival rate is higher for dental implants placed in the mandible than for those in


13

the maxilla (23). It is evident that, when compared with the maxilla, the bone surrounding the

implant has better volume and quality in the mandible (24).

Barone A, Rispoli L, Vozza I, Quaranta A, Covani U et al(2006)8 In extreme,

this involves insertion of an implant immediately after tooth extraction, potentially using

simplified procedures such as flapless surgery, and subsequent restoration of the implant in the

same session. Ultimately, this combination may not only lead to a reduction in the overall

treatment time, but may also substantially decrease the associated costs. Furthermore, it has been

claimed that the described approach is clearly associated with reduced surgical procedures and

may more efficiently preserve the existing bone and soft tissues at the site of implantation.

Paulo Malo DDS et al (2006)36 In his pilot study indicated that fully edentulous

Jaws with various types of bone quality can be treated with high success and good aesthetics

using immediately loaded implants featuring a narrow implant apex reduced color height and an

anodically oxidized implant surface and that favorable margin bone loss can be maintained.

Vandamme(2007)44 study also showed that threaded implants offer significant

bone-to-implant contact during which may also enhance the secondary stability. Hence, cylinder-

type implants seem to be contraindicated for immediate loading regimes due to lowering of

primary stability and less resistance to vertical movement and shear stress.

Horwitz(2007) 30implied in his study the survival and success rates of immediate

loaded implants seemed to be similar to those of the traditional protocol. Immediate loading


14

provided with several advantages such as increased masticatory function, stability to the interim

prosthesis, minimizing uncontrolled transmucosal loading, preservation of bone and stimulation

of bone remodelling, enhancement of gingival contours and better esthetic. It is also reported

with the improvement of psychological impact (34, 35). Despite several advantage of immediate

loading, there is no agreement on the technique by which immediate loading can be achieved.

The success of immediate loading relies on the technological advances in the texture, shape and

material of the implant. In addition to immediate loading the primary stability depends even on

the bone quality and density.

Barewal RM(2007) 7 stated the primary stability of implant achieved at the time

of implant placement and it is also associated with bone density, length, width and type of

implant and drilling technique. The primary stability obtained after implant placement is

considered a relevant factor for the prognosis of the implant and has been identified as a

prerequisite to achieve osseointegration. This would suggest that high primary stability that

makes immediate loading more predictable (20).

Ana vargas Solana etal (2008).3 evaluated the evidence available in the literature

regarding resonance frequency analysis for the determination of primary stability with regard to

its utility in decision making in immediate loading protocol and concluded that RFA may help

clinician to choose among various loading protocols and to selectively monitor implants during

the healing phase.


15

Romanos GE(2008)37 have stated the varying designs of implants with various

degrees of stability and determine their future clinical performance. Hence, he quoted that screw

or “threaded” design minimizes the implants micro motion during function thereby maintaining

the PS. Furthermore, a threaded design also increases the surface area of the implant thereby

offering a higher percentage of bone-to-implant contacts, in comparison to implants with a

cylindrical design. Therefore, threaded type implants are generally recommended and

particularly for immediate loading.

EspositoM, Grusovin MG, Willings M, Coulthard P, Worthington HV,

Esposito M et al(2009)18 proposed different time frames for loading dental implants in

replacement of missing tooth.

Fawad javed etal (2010) 20 Assessed the role of primary stability for successful

immediate loading of dental implants. And its evident that the degree of achieved primary

stability during immediate loading protocols is depend on several factors including bone density

and quality, implant shape, design, surface characteristics and surgical technique. Further

research is required in situation, such as poor bone quality and quantity and multiple implant or

augmentation procedure, which may challenge the attainment of primary stability during

immediate loading.

Fung LJ et al(2010)22 have demonstrated the clinical outcome of an implant by

many factors, including the implant body, skill of surgeon, and the oral environment. Few other


16

studies have demonstrated that the quality of the alveolar bone is the most important factor for

achieving good primary stability (21).

Heng-Li Huang (2010).26 Investigated implant stability using resonance

frequency measurement of topographically changed and surface chemistry modified implants in

rabbit bone. And found that implant surface properties influence RFA measurements of implant

stability. surface chemistry modified titanium implants showed higher values than

topographically changed implants.

Sun jong kim ,Myung Kim –et al(2010)41 Proposed in the animal study that the

bone to implant contact ratio was higher in surfaces with a roughness of 1.02 [73.6%+14.4%]

SLA treated and in surfaces with a roughness of 1.76 [ 69.6%+ 12.5%] than in surfaces with

roughness of 0.86 m[60.82%+13.11]. There were no significant difference between the 3groups

of various surfaces in terms of implant stability.

.

Fung et al et al(2011)22 He concluded that after 36 months of functional loading

there was no significant difference in the change in radiographic bone levels between titanium

oxide- anodized & machined surface MKIV dental implants. From 12 to 36 months of functional

loading ,both anodized machined surfaces implants exhibited gains in RBL(Radiographic Bone

Level) which statistically significant for the machined implants.

Antonin sinmunek etal (2012) 40. Monitor the development of stability of

immediately loaded implants during early healing and concluded that implant with low primary


17

stability showed significant increase in stability over time and increase in stability during

healing. In contrast, implant with high primary stability lost some stability over time.

Jan gottlow etal (2012)29. Experimental investigation was done to compare the

bone tissue responses and implant stability between two commonly used implants representing

different geometries and surface characteristics. Both HSBA and OX implants were well

integrated in bone and showed firm and increased stability from placement to after 6 weeks of

healing. The HSBA implant showed more BIC after 10 days and OX implant more BIC after

6week of healing. The HSBA implant showed significantly higher shear strength after 3 and

6weeks and higher RTQ values after 3 weeks than OX implant. This result may be due to

difference in surface roughness and hydrophilic properties.

.

Gerard torroella saura, Javier mareque etal (2014)24. Evaluated the effect of

two different designs, tapered vs cylindrical, on primary stability of implants placed with an

immediate loading protocol in edentulous mandible to support fixed prosthesis with in occlusal

contacts during first 48hr and concluded that tapered implant achieved greater primary stability

values measured with ITVs and less marginal bone loss than the cylindrical implants

Alessandiopozi, Marco Talliarico et al (2014) 2Compared the clinical &

radiological outcomes of two implant designs [Noble active & Noble speedy groovy ] with

different prosthetic interfaces and neck configuration and explained that lower marginal bone

loss around that conical connection of noble active implant in comparison with flat to flat

implant abutment interface with noble speedy groovy implants. The clinical parameters [SBI &


18

PS]were absolutely insignificant in well maintained patients & concluded that MBL changes

could be affected by the different implant designs A high ISQ values was found for both

implants & no statistically significant differences was found for ISQ mean values b/w

interventions .

Bilal Al nawas etal (2014)12. Investigated in a split mouth model whether small

diameter implants made from titanium-13 zirconium alloy perform at least as well as titanium

grade IV implants. This study confirms the TiZr small diameter bone level implants provide at

least the same out comes after 12 mounths as grade IV bone level implants. This improved

mechanical properties of TiZr may extend implant therapy to more challenging situations.

Lester Du Preez et al 32 (2014)conducted a study based on longevity and

functionability of three different implant designs – Hydroxyapatite, Ceramics, titanium (Plasma

Sprayed/ Pure/Alloy) in the same patient and concluded that different designs of implant system

have no bearing on the longevity or functional success of the units used at least in the anterior

mandible.

MATERIALS AND METHODS

19

The present in vivo study was conducted for the comparative evaluation of

clinical stability of two different types of implants with different surface treatments namely i) Al

Oxide blasted / acid etched surface & ii) Resorbable blast medium (RBM) ( Calcium phosphate)

treated surface loaded immediately with a fixed full arch prosthesis.

The following materials , instruments and equipment were used for the study.

MATERIALS USED:

1. Root form endosteal implants (Al Oxide blasted / acid etched surface )- Touareg-S (Adin

implant system, Adin pvt ltd,Israel)

2. Root form endosteal implants ( Resorbable blast medium (RBM) ( Calcium phosphate)

treated surface) - Touareg-OS (Adin implant system, Adin pvt ltd, Israel)

3. Smart peg type 49 (OSSTELL MENTOR, Gothenborg, Sweden).

4. CAD-CAM fabricated Titanium frame work (TDS ME 300 HP,TDS

Biotechnologies,Taiwan)

5. Polyether impression material (pentasoft monophase,Pentamix-2,3M ESPE, Seefeld ,

Germany )

6. Tray adhesive (3M ESPE, Seefeld , Germany )

7. Soft tissue gingival mask (DETAX ,Ettlingen, Germany)

8. Open tray transfers-implant level (Adin implant system, adin pvt ltd, Israel )

9. Implant replicas. (Adin implant system, adin pvt ltd, Israel)

10. Healing collars. (Adin implant system, adin pvt ltd, Israel)

11. Bite registration paste.(exabite , Ivoclar vivadent ,Schaan, Italy )

12. Heat cure acrylic resin. (DPI, Mumbai)


20

13. Auto polymerizing acrylic resin-pink. (DPI, Mumbai)

14. Auto polymerizing acrylic resin –clear. (DPI, Mumbai)

15. Cross linked acrylic teeth (Gnathostar, Ivoclar Vivadent Inc,NY ,USA ) .

16. Stainless steel sleeves.

17. Light cure Composite resin ( GC CORPORATION,Tokyo, Japan)

18. 2% lignocaine with adrenalin (1: 200,000) (Lignox, Indoco remedies pvt ltd .Mumbai)

19. Povidone-Iodine solution 2 % (Betadine ,wockhardt,India ) .

20. Polyethylene glycol suture (vicryl 3-0ETHICON, Johnson & Johnson, Aurangabad)

INSTRUMENTS USED

1)Implant surgical kit (Adin implant system, adin pvt ltd.,Israel).

-Initial drill (lancet drill)

-2.0mm twist drill -.

-2.8 mm twist drill.



Paralleling pin.

Depth gauges (short and long)

2) Implant driver.


21

3) Hex driver.

4) Caliberated torque wrench.

5) Bard Parker knife no:3

6) Bard parker blade no :15.

7) Howarth’s periosteal elevator.

8) Austins retractor.

9) Cheek retractor.

10) Vestibular retractor.

11) Tissue forceps.

12)Needle holder.

13) Scissors.

14) Semiadjustable articulator with facebow (Hanau wide vue, whipmix corp, USA)

EQUIPMENTS:

1. Cone beam CT machine (Cone Beam CT CS 9300,Carestream , France)

2. Implant motor with Physio dispenser ( Saeshin, korea )

3. Radio visio graph.(RVG) (Carestream ,France )

4. Resonance frequency analyser -OSSTELL MENTOR ( Gothenborg, Sweden)


22

5. Optical Scanner (Shining 3D, TDS biotechnologies ,Taiwan)

6. TDS ME 300 HP - 5 axis milling machine (TDS biotechnologies ,Taiwan)

7. Pentamix 2 automixing device (3M ESPE ,Seefeld,Germany)

Description of Resonance Frequency Analysis (RFA) & Osstell machine

The RFA technique is essentially a bending test of the bone-implant system in

which an extremely small bending force is applied by stimulating a transducer. It is equivalent in

terms of direction and type to applying a fixed lateral force to the implant measuring the

displacement of the implant. This effectively mimics clinical loading conditions, although on a

much reduced scale. The RFA method can potentially provide clinically relevant information

about the state of the implant-bone interface at any stage of treatment.

The RFA analyser used in the present study is the Osstell mentor developed by

Meredith et al, Gothenburg, Sweden. It consists of a metal rod (Smart peg) attached to the

implant with a screw connection. The rod has a small magnet attached to its top that is stimulated

by magnetic pulses from a handheld electronic device. The magnetic waves are of sinusoidal

form .The rod mounted on the implant has two fundamental resonance frequencies; it vibrates in

two directions, perpendicular to each other. One of the vibrations is in the direction where in the

implant is most stable. The frequency of the registered oscillation depends on the stiffness of

bone – implant attachment. The stiffer the system , the higher the transducer’s oscillating

frequency will be. Thus two ISQs (Implant Stability Quotient) are provided. The ISQ values are

displayed on the screen of the hand held electronic device. For example, an implant with

buccally exposed threads may show one low value, reflecting the lack of bone in the buccal-

lingual direction, and one high value , reflecting good bone support in the mesial-distal direction.


23

Usually the average of the two values are taken to be the ISQ of that particular implant . The

implant stability quotient is a nearly linear mapping from resonance frequency measured in kHz

to the more clinically useful scale of 1-100 ISQ. The higher the ISQ ,the more stable the implant.

METHODOLOGY

I. Formulation of study design

a. Split mouth prospective trial

b. Formulation of null hypothesis

c. Inclusion and exclusion criteria

d. Informed consent

II. Patient selection

III. Fabrication of complete denture

IV. Fabrication of radiographic template

V. Cone beam CT evaluation

VI. Implant placement

VII. Assessment of primary implant stability

VIII. Fabrication of hybrid prosthesis

a.impression making

b.framework trial

c.jaw relation and wax trial

d.insertion of hybrid prosthesis

IX. Assessment of implant stability – 1 month , 3 months,6 months and 12 months

intervals.

X. Tabulation of data & Statistical analysis.


24

I. FORMULATION OF STUDY DESIGN :

a. Split mouth prospective trial

The present in-vivo study is designed to be a split mouth prospective clinical trial in

which each patient received both the types of implants investigated in either of the two

quadrants of the mandibular arch - right or left .Each group of implants was placed on

one side of the arch (n-=3) for each patient. A total of 5 patients were included in the

study resulting in 15 implants of each group being placed. The Alumina oxide blasted /

acid etched surface (TOUAREG-S) is taken as the control (Group A) and the Resorbable

blast media (RBM) surface (TOUAREG-OS) is taken as the test group(Group B) . The

side selection –right or left for each group is randomized according to the randomization

schedule give below.

Table 1 : Randomisation schedule for implant placement

SITE Intra oral

region

Patient 1 Patient 2 Patient 3 Patient 4 Patient 5

I 46-47 A B B A A

II 44-45 A B B A A

III 43 A B B A A

IV 33 B A A B B

V 34-35 B A A B B

VI 36-37 B A A B B


25

A - Alumina oxide blasted / acid etched surface (TOUAREG-S)

B - Resorbable blast media (RBM) surface (TOUAREG-OS)

The study is a triple blind Prospective clinical trial in which the subject,

operator and investigator are blinded. An independent research associate prepares the

randomization schedule and hands over the implant accordingly to the operator during

implant placement. The assessment of the clinical stability is again done by an

independent investigator who measures the stability at fixed time intervals namely

a. Immediately after implant placement.

b. One month after implant placement.

c. Three months after implant placement.

d. Six months after implant placement.

e. Twelve months after implant placement.

b.Formulation of the null hypothesis.

Null hypothesis for this study is that there is no difference in the clinical stability of the

two implant surfaces over a period of one year.

c. Inclusion and exclusion criteria.

Inclusion and exclusion criteria for Participation in the study

Inclusion criteria

Voluntary informed consent

Age >45 years and ≤ 65 years

Completely edentulous maxilla and mandible at the time of surgery

Last tooth extracted more than 8 weeks before date of surgery


26

Available bone height of atleast 10 mm in the molar region, 13 mm in the premolar region

and 16 mm in the canine region of the edentulous mandible.

Available bone width of atleast 7mm in molar region, 6 mm in premolar region and 6 mm in

canine region of the edentulous mandible.

Commitment to participate in the study for atleast 1 year of follow-up examinations

Exclusion criteria (systemic)

Medical conditions requiring prolonged use of steroids

Severe hemophilia

Bisphosphonate medication

History of leukocyte dysfunction and deficiencies

History of head and neck radiation or chemotherapy

History of renal failure

History of uncontrolled endocrine disorders

Physical handicaps interfering with ability to perform adequate oral hygiene

Use of any investigational drug or device within 30 days prior to implant surgery

Alcoholism or drug abuse

HIV infection

Smoking >10 cigarettes or cigar equivalents per day or chewing tobacco> 10 cigarette

equivalents per day .

Conditions or circumstance which would prevent completion of study participation or

interfere with analysis of study results (eg. Non- compliance)


27

Exclusion criteria (local)

Local inflammation including denture stomatitis.

Mucosal diseases such as erosive lichen planus

History of local irradiation therapy

Presence of osseous lesions

Unhealed extraction sites

History of bone reconstruction and bone grafting techniques at site of intended implant

placement.

Severe bruxing or clenching habits

Persistent intraoral infection

Patients with inadequate oral hygiene or unmotivated for adequate home care

Exclusion criteria (secondary)

Need for GBR treatment at implant surgery

Insufficient bone or any other bone abnormality that contraindicated placement

Inappropriate treatment according to study protocol.

Lack of primary implant stability at time of abutment connection (ie, spinning implant at 35

Ncm torque or laterally moving implant)

d.Informed consent. (Annexure 1)

The study proposal was presented before the ethical committee and

institutional review board of the study center and clearance was obtained for the

proposal. All the subjects who fulfilled the above inclusion and exclusion criteria were

counselled regarding the treatment options and the research element involved in it. They


28

were free to ask any questions and were clarified. A written consent was obtained from

those subjects who were willing to participate in the study.

II.PATIENT SELECTION :

The completely edentulous patients who reported to the department of

prosthodontics of the study center were screened to fulfill the inclusion and exclusion criteria. A

detailed general examination and local examination was done for the prospective study

population. A panoramic radiograph as a part of the routine investigation for complete denture

therapy is also obtained. Based on these clinical and radiographic assessments, the final safety

population of five patients (male = 4, female =1) was selected.

III.FABRICATION OF COMPLETE DENTURE :

A conventional complete denture was constructed for each patient. Preliminary

impression trays were made with stock tray using irreversible hydrocolloid impression material (

alginate – Algitex ,DPI ,India). Special trays were constructed using auto polymerising

polymethyl methacrylate resin (DPI, India). Border moulding is done with low fusing compound

(DPI, India ) and final impressions were made with medium body polyether impression material

(Pentamix-2,3M ESPE) . Wax occlusal rims (Hindustan dental, India) were constructed on

record bases and face bow transfer (hanau spring bow, whipmix corp, USA) was done. Centric

jaw relation was recorded and the casts were mounted in a semi adjustable articulator( Hanau

wide vue, whipmix corp, USA) .Teeth arrangement was done using anatomical tooth form

(Gnathostar,Ivoclar Vivadent Inc,NY ,USA) employing the standard principles. Trial set up was

verified in the patient’s mouth for aesthetics , phonetics and occlusion and was then processed in

heat polymerizing polymethyl methacrylate resin(DPI, India).The dentures were then inserted in


29

the patient’s mouth and the necessary occlusal adjustments were done clinically. The patients

were instructed regarding denture wear and maintenance.

IV.FABRICATION OF RADIOGRAPHIC TEMPLATE

Patients were recalled after one week and the lower denture was alone then

duplicated in clear auto polymerizing acrylic resin( DPI, India). The duplication was done by

investing the denture in a duplicating flask. Radio-opaque markers (gutta percha) were placed

along the long axis of the canine, pre molar and molar teeth extending the whole length from the

occlusal surface to the denture base. Thus a radiographic template was obtained to evaluate the

bone volume in the area of interest..

V. Cone Beam CT EVALUATION

A cone beam computerized tomographic evaluations (Cone Beam CT CS

9300,Carestream , France) of the mandible was done with the patient wearing the radiographic

template. The images were then analyzed for three dimensional evaluation of bone quality in the

pre determined site for the implant placement. The available bone height, mesio distal and bucco

lingual width at each site was noted down in the clinical case record of the patient. One subject

who showed deficient bone volume in the posterior mandible was relieved from the study and

one more patient was added who fulfilled the eligibility criteria.

VI.IMPLANT PLACEMENT :

A surgical template was fabricated from the radiographic template by removing

the radio opaque marker with a rotary cutting instrument and the channels where the markers


30

were placed earlier were widened to accommodate 2mm wide hollow stainless steel metal

sleeves . The sleeves were secured in position by flowing a thin mix of clear auto polymerizing

resin into the channels and then inserting the sleeves into the channels. The guiding sleeves were

placed only in the areas of proposed implant placement and serve as a guide to position the pilot

drill for intial osteotomy. The surgical template thus obtained was cold sterilized by immersion

in 2 % gluteraldehyde solution( cidex) for 20 minutes.

1. The patients were given a single oral dose of 2 g Amoxycillin (Mox 500,Ranbaxy ,India)

one hour before the implant sugery. Skin disinfection was done with povidone iodine

paint (Betadine ,wockhardt,India). The patient was asked to rinse the mouth with 2%

chlorhexidine mouthwash (Rexidin ,ICPA,India) for 3 to 5 minutes. Surgical draping was

done . Local anesthesia was achieved with 2 % lignocaine with adrenalin 1 : 200,000

(Lignox, Indoco remedies, Mumbai) infiltrated along the buccal and lingual aspects of the

mandible. No nerve block was given. The surgical template was placed over the

edentulous mandibular ridge and pilot osteotomies were done .The surgeon made sure the

pilot drills were inside the bone by tactile sensation and measuring the drill depth and

correlating it with the CBCT measurements. The surgical guide was then removed and a

crestal incision was made with BP blade no 15 and a full thickness mucoperiosteal flap

was reflected. The pilot osteotomies made earlier were identified by the bleeding points

and also by probing. Sequential osteotomies were done with successive drills in each site

to specifically accommodate the predetermined implant sizes as given below :


31

Table 2 : Intra oral sites and corresponding implant dimensions

SITE Intra oral region Implant length Implant diameter

I 46-47 8 mm 4.2 mm

II 44-45 11.5 mm 3.75 mm

III 43 13 mm 3.75 mm

IV 33 13 mm 3.75 mm

V 34-35 11.5 mm 3.75 mm

VI 36-37 8 mm 4.2 mm

The osteotomies were prepared using a contraangle surgical handpiece ( NSK

corporation, Japan) mounted on an implant motor (Saeshin, korea) under copious irrigation of

cold normal saline( Dexter laboratories , India) under 800 to 1200 rpm speed . All the

osteotomies on one side of the arch were completed first and the implants were inserted before

the contralateral side osteomies were started.

The implants were assigned to site by the independent research assistant

according to the randomization schedule prepared earlier. The implant group and size were

verified and the implants were uncovered from the outer package by the research assistant and

only the sterile glass vials containing the implants were handed over to the surgeon. The

operator bias was thus eliminated since both groups of implants look similar macroscopically.


32

All the implants were placed by the same surgeon for all the study participants inorder to

eliminate inter operator bias.

VII . ASSESSMENT OF PRIMARY IMPLANT STABILITY

The implants were hand torqued in place and were indexed for favourable

emergence. The insertion torque value for each implant was measured in N Cm by means of the

calibrated torque wrench and was noted down as assessed by the surgeon. The calibrated torque

wrench has readings corresponding to values of 35 Ncm , 50 Ncm,70 Ncm and 100 Ncm. The

insertion torque values were taken in reference to the nearest calibration .For example , an ITV

between 35 and 50 Ncm is considered to be as >35 Ncm. No definitive numerical value can be

obtained but a range is obtained for each implant and scores are assigned based on these

ranges. ( table no.6)

The Implant stability quotient (ISQ) values were assessed using the Resonance

frequency Analyser ,( RFA) (Osstell Mentor,Gotenborg,,Sweden) by the investigator who will

also measure the periodical ISQ values throughout the study. The measurement of ISQ values

begins with connection of a smart peg (type 49 ,Osstell Mentor, Gotenborg, Sweden) to the

implant. The smart peg is a wireless magnetic transducer designed to fit the internal hexagon of

the implant and is screwed into place by an attached handle. They are finger tightened and the

RFA probe was then placed in close proximity to the smart peg on the buccal side .Care was

taken not to touch the smart peg with the probe . The ISQ value displayed on the screen of the

RFA instrument was recorded. The same procedure was carried out on the mesial side and the

ISQ value obtained. The procedure is then repeated for all the implants one at time and ISQ

values noted down.


33

After assessment of the primary stability of the implants as described above , the

implants were covered with a healing collars which were atleast 1 mm above the peri implant

soft tissue. Flap closure was obtained by means of multiple interrupted sutures using

polyethylene glycol ( vickryl, ethicon, India). The patients were prescribed a course of antibiotics

( amoxycillin ) for 5 days and analgesics ( ketorolac) for 3 days. They were also instructed to use

2 % chlorhexidine mouthwash twice daily for 1 month postoperatively.

VIII.FABRICATION OF HYBRID PROSTHESIS

The implants were subjected to immediate functional loading within 1 week of

placement. An implant level screw retained metal – acrylic hybrid prosthesis was fabricated as

follows :

A.IMPRESSION MAKING:

After completion of suturing, the healing collars were removed one by one and

implant level open tray transfers were connected. The open tray transfers were splinted together

using pattern resin .The resin connection was sectioned in between the implants and were

connected together again so as to minimize polymerization shrinkage and facilitate accurate

transfer of relative implant positons. A special tray was fabricated from auto polymerising resin

from the pre operative edentulous cast. The tray was tried in the patients mouth and necessary

adjustments were made so as to facilitate proper seating of the tray and coverage of the tray

transfers. Tray adhesive was applied and impression was made with medium body polyether

impression material (pentasoft monophase) using automixing device( pentamix 2).Impression

was removed from the patients mouth by loosening the guide pins of the tray transfers. The

healing collars were then replaced in the patients mouth.Implant replicas were connected to the


34

impression and soft tissue mask was poured. A working model is obtained by pouring type III

dental stone (kalabhai, India).

B.FRAMEWORK TRIAL

The model was scanned with a scanner (shining 3D , TDS biotechnologies

,Taiwan) and an implant level titanium milled frame work was obtained.(TDS ME 300 HP - 5

axis milling machine., TDS biotechnologies ,Taiwan).The CAD-CAM fabricated metal

framework is tried on the second or third post operative day and a panaromic radiograph is taken

to verify the fit of the frame work.

C) JAW RELATION AND WAX TRIAL

A Wax occlusal rim was fabricated on the metal frame work and jaw relation was

made opposing the existing maxillary denture. Esthetics , phonetics , occlusal plane and vertical

dimension were established. Centric relation record was obtained opposing the existing maxillary

denture using Bite Registration paste (exa bite,GC ASIA).The model and the existing maxillary

denture were mounted in a semi adjustable articulator using this jaw relation record. Teeth

arrangement(Gnathostar,Ivoclar Vivadent Inc,NY ,USA) was done and a wax trial was seen in

the patients mouth. A Lingualised occlusal scheme was obtained .

D) INSERTION OF HYBRID PROSTHESIS

The wax trial was processed in heat polymerized acrylic resin and metal acrylic

hybrid prosthesis is obtained. The prosthesis is designed to be without any flanges or palatal

plate. A slight tissue contact with the edentulous ridge is maintained by the smooth , convex

inner surface of the hybrid prosthesis. On the sixth or seventh postoperative day the hybrid

prosthesis was inserted in the patients mouth and the prosthetic screws were torqued to 15 Ncm


35

using calibrated torque wrench. Occlusion was verified and minor occlusal adjustments if any

was done in the dentures. The screw access channels in the hybrid denture were closed with a

plug of cotton and light cure composite resin . The patient was instructed on oral hygiene

maintenance and advised to restrain chewing very hard food items. However the patient was

advised to continue his normal food habits. Patients were counseled regarding the recall visits

and their continued participation in the study.

IX. Assessment of implant stability – 1 month , 3 months,6 months and 12 months

intervals

The patients were recalled at an interval of 1 month after implant

placement and immediate loading with metal – acrylic hybrid prosthesis. The prosthetic

screws were accessed by removing the composite resin over the screw access channels

with an airotor mounted tungsten carbide bur . The cotton pellet is also removed and the

prosthetic screws were disengaged one by one using a hand wrench. The hybrid

prosthesis is removed from the implant heads and the exposed implant internal hexagons

are irrigated with saline solution. The smart pegs are attached at the implant level and

ISQ values are obtained using the Resonance Frequency Analyser in a manner similar to

that obtained during implant placement. The measurement is done by the blinded

investigator and noted down .The prosthesis is then screwed back in place and patient is

instructed regarding the subsequent follow up visit. ISQ values were obtained in a

similar manner for periods of 1 month , 3 months , 6 months and 12 months after implant

insertion and immediate prosthetic loading.


36

X.Tabulation of data & Statistical analysis

The study was unblinded after 12 months and the ITV and ISQ values were

tabulated according to the study groups. The tabulated data was subjected to statistical analysis

to fulfill the objectives of the study and to test the null hypothesis. Statistical analysis was done

using the software SPSS version 16.


37

METHODOLOGY – OVERVIEW

Methodology – Overview

Formulation of Study Design

Inclusion & Exclusion Criteria

Case Selection (n = 5) &

Informed Consent

Fabrication of Complete denture

Fabrication of Radiographic template

CBCT Evaluation

Implant Placement (n=30)

Immediate Functional Loading With Hybrid Denture

Aluminium Oxide Blasted / Acid etched

Resorbable Blast Medium Treated (n=15)

Evaluation Of Implant Stability (ISQ) at 1 month, 3 months, 6 months & 12 months

Unblinding of Study & Tabulation of Results

Statistical Analysis

Materials and

Methods

Results

RESULTS

38

The present in vivo study was conducted for the comparative evaluation of

clinical stability of two different types of implants with different surface treatments namely i) Al

Oxide blasted / acid etched surface & ii) Resorbable blast medium (RBM) (Calcium phosphate)

treated surface loaded immediately with a fixed full arch prosthesis.

The test samples (implants) were grouped as follows :

Group A - Al Oxide blasted / acid etched surface (Touareg S) (n=15)

Group B - Resorbable blast medium (RBM) (Calcium phosphate) treated surface (Touareg OS)

(n=15).

The samples were placed in 5 patients who received 3 implants of each group in

either of the two quadrants of the mandibular edentulous ridge (split mouth design). The initial

and progressive stability of these two groups of implants were assessed and the results obtained

are tabulated as follows :

RESULTS

39

Table 3: Insertion torque values (ITV ) in NCm

Table 4 : Insertion torque values (ITV ) in NCm for Al oxide blasted / acid etched surface

Case no Site I Site II Site III Site IV Site V Site VI Case 1 >50 50 50 70 >50 70 Case 2 >35 70 70 50 50 50 Case3 >70 >70 70 70 50 50 Case 4 >70 >35 70 >70 >35 50 Case 5 >50 70 70 70 >50 >50

Case 1

>50

50

50

Case 2

50

50

50

Case 3

>70

>70

70

Case 4

>70

>35

50

Case 5

>50

70

70

RESULTS

40

Table 5 : Insertion torque values (ITV ) in NCm for Resorbable blast medium treated

surface

Case 1

70

>50

70

Case 2

>35

70

70

Case 3

70

50

50

Case 4

>70

>35

70

Case 5

70

>50

>50

RESULTS

41

Table 6 : Insertion torque Values and corresponding Scores.

ITV RANGE (NCm) SCORE

0 – 35 0

36 - 50 1

51 – 70 2

71 – 100 3

Table 7 : Comparison of Insertion torque values (ITV ) of Al Oxide blasted / acid etched

surface (Group A) and Resorbable blast medium (RBM) treated (Group B)

implants

Group N Mann – whitney U value

P value

A 15

102.500 0.34 B 15

RESULTS

42

Table 8: Site specific Implant Stability Quotient (ISQ) values

SITE 0

MONTHS 1

MONTH 3

MONTHS 6

MONTHS 12

MONTHS

CASE 1

I B 71 50 68 78 79 M 68 51 77 80 80

II B 68 58 71 75 79 M 72 60 63 77 77

III B 55 51 70 75 74 M 63 55 56 72 76

IV B 75 58 71 79 80 M 77 59 70 82 83

V B 70 57 66 79 76 M 72 58 69 78 79

VI B 75 53 64 77 75 M 74 54 68 78 78

CASE 2

I B 65 52 68 70 74 M 72 59 70 75 79

II B 62 51 65 68 70 M 69 58 60 65 69

III B 66 52 70 75 75 M 69 54 68 72 70

IV B 51 49 64 70 72 M 74 55 72 76 76

V B 61 51 65 71 72 M 62 54 68 70 69

VI B 64 55 70 74 72 M 52 48 72 76 78

CASE 3

I B 75 55 71 74 79 M 80 58 75 76 80

II B 65 59 76 76 80 M 70 58 78 78 76

III B 80 58 79 80 80 M 78 59 77 79 79

IV B 75 56 76 77 74 M 77 58 74 78 79

V B 70 54 72 75 75 M 72 58 74 79 80

VI B 75 51 68 81 82 M 74 56 79 80 80

B- Buccal M- Mesial

RESULTS

43

Table 8 Continued:

SITE 0

MONTHS 1

MONTH 3

MONTHS 6

MONTHS 12

MONTHS

CASE 4

I B 75 58 65 73 75 M 80 59 70 77 76

II B 65 52 66 75 76 M 70 54 72 79 78

III B 80 62 74 80 80 M 78 60 75 79 80

IV B 75 58 71 79 78 M 77 59 70 82 80

V B 70 57 66 79 79 M 72 58 69 78 80

VI B 75 53 64 77 76 M 74 54 68 78 78

CASE 5

I B 68 50 70 72 72 M 66 52 68 70 70

II B 62 53 65 74 72 M 65 51 68 72 70

III B 68 55 70 74 76 M 67 52 72 75 75

IV B 66 54 69 74 78 M 68 54 68 78 78

V B 64 53 68 80 79 M 61 50 69 81 80

VI B 60 51 70 78 78 M 63 52 70 80 81

B- Buccal M- Mesial

RESULTS

44

Table 9 : Implant Stability Quotient (ISQ) values for Al oxide blasted / acid etched surface

(group A)

SITE 0 MONTH 1 MONTH 3

MONTHS 6

MONTHS 12

MONTHS

CASE 1 1 69.5 50.5 72.5 79 79.5 2 70 59 67 76 78 3 59 53 63 73.5 75

CASE 2 4 62.5 52 68 73 74 5 61.5 52.5 66.5 70.5 70.5 6 58 51.5 71 75 75

CASE 3 4 76 57 75 77.5 76.5 5 71 56 73 77 77.5 6 74.5 53.5 73.5 80.5 81

CASE 4 1 77.5 58.5 67.5 75 75.5 2 67.5 53 69 77 77 3 79 61 74.5 79.5 80

CASE 5 1 67 51 69 71 71 2 63.5 52 66.5 73 71 3 67.5 53.5 71 74.5 75.5

Table 10 : Implant Stability Quotient (ISQ) values for Resorbable blast medium treated

surface (group B)

SITE 0

MONTHS 1 MONTH

3 MONTHS

6 MONTHS

12 MONTHS

CASE 1 4 76 58.5 70.5 80.5 81.5 5 71 57.5 67.5 78.5 77.5 6 74.5 53.5 66 77.5 76.5

CASE 2 1 68.5 55.5 69 72.5 76.5 2 65.5 54.5 62.5 66.5 69.5 3 67.5 53 69 73.5 72.5

CASE 3 1 77.5 56.5 73 75 79.5 2 67.5 58.5 77 77 78 3 79 58.5 78 79.5 79.5

CASE 4 4 76 58.5 70.5 80.5 79 5 71 57.5 67.5 78.5 79.5 6 74.5 53.5 66 77.5 77

CASE 5 4 67 54 68.5 76 78 5 62.5 51.5 68.5 80.5 79.5 6 61.5 51.5 70 79 79.5

RESULTS

45

Table 11 : Comparison of mean implant stability quotient (ISQ) values of Al Oxide blasted

/ acid etched surface (Group A) at different time intervals

N

MEAN

STANDARD

DEVIATION

F

VALUE

‘p’

VALUE

0 month 15 68.2667 6.58425

67.233

.000**

1 month 15 54.2667 3.23412

3 months 15 69.8000 3.47337

6 months 15 75.4667 2.99086

12 months 15 75.8000 3.23927

total 75 68.7200 8.84026

RESULTS

46

Table 12 : post hoc comparison of implant stability quotient (ISQ) of Al Oxide blasted /

acid etched surface (Group A) at different time intervals

Tukey’s HSD test

(I) (J)

Mean

Difference (I-

J)

Std. Error Sig.

0 month

1 month 14.00000* 1.50833 .000

3month -1.53333 1.50833 .847

6months -7.20000* 1.50833 .000

12months -7.53333* 1.50833 .000

1 month

0 month -14.00000* 1.50833 .000

3month -15.53333* 1.50833 .000

6months -21.20000* 1.50833 .000

12months -21.53333* 1.50833 .000

3month

0 month 1.53333 1.50833 .847

1 month 15.53333* 1.50833 .000

6months -5.66667* 1.50833 .003

12months -6.00000* 1.50833 .002

6months

0 month 7.20000* 1.50833 .000

1 month 21.20000* 1.50833 .000

3month 5.66667* 1.50833 .003

12months -.33333 1.50833 .999

12months

0 month 7.53333* 1.50833 .000

1 month 21.53333* 1.50833 .000

3month 6.00000* 1.50833 .002

6months .33333 1.50833 .999

RESULTS

47

Table 13 : Comparison of mean implant stability quotient (ISQ) values of Resorbable blast

medium (RBM) treated surface (Group B) at different time intervals

N MEAN

STANDARD

DEVIATION

F

VALUE

‘p’

VALUE

0 month 15 70.6667 5.44343

77.560

.000**

1 month 15 55.5000 2.59808

3 months 15 69.5667 4.02611

6 months 15 76.8333 3.77334

12 months 15 77.5667 3.04647

total 75 70.0267 8.84395

RESULTS

48

Table 14 : Post hoc comparison of implant stability quotient (ISQ) of Resorbable blast

medium (RBM) treated surface (Group B) at different time intervals

Tukey’s HSD test

(I) (J)

Mean

Difference (I-

J)

Std. Error Sig.

0 month

1 month 15.16667* 1.42464 .000

3month 1.10000 1.42464 .938

6months -6.16667* 1.42464 .000

12months -6.90000* 1.42464 .000

1 month

0 month -15.16667* 1.42464 .000

3month -14.06667* 1.42464 .000

6months -21.33333* 1.42464 .000

12months -22.06667* 1.42464 .000

3month

0 month -1.10000 1.42464 .938

1 month 14.06667* 1.42464 .000

6months -7.26667* 1.42464 .000

12months -8.00000* 1.42464 .000

6months

0 month 6.16667* 1.42464 .000

1 month 21.33333* 1.42464 .000

3month 7.26667* 1.42464 .000

12months -.73333 1.42464 .986

12months

0 month 6.90000* 1.42464 .000

1 month 22.06667* 1.42464 .000

3month 8.00000* 1.42464 .000

6months .73333 1.42464 .986

RESULTS

49

Table 15 : Comparison of implant stability quotients (ISQ) of Al Oxide blasted / acid

etched surface (Group A) and Resorbable blast medium (RBM) treated surface

(Group B) implants at different time intervals.

Time

period Group N Mean SD F p

0 month

A

B

15

15

68.267

70.667

6.5843

5.4434

0.383

0.541

1 month

A

B

15

15

54.267

55.500

3.2341

2.5981

0.676

0.418

3months

A

B

15

15

69.800

69.567

3.4734

4.0261

0.002

0.962

6

months

A

B

15

15

75.47

76.83

2.991

3.773

0.181

0.674

12

months

A

B

15

15

75.80

77.57

3.239

3.046

0.294

0.592

RESULTS

50

Graph 1 : Mean ISQ values of Al Oxide blasted / acid etched surface (Group A)

Graph 2 : Change in ISQ over 1 year period for Al Oxide blasted / acid

etched surface (Group A)

68.26

54.26

69.8

75.46 75.8

1 2 3 4 50 Month 1 months 3 Months 6 Months 12 Months

68.26

54.26

69.8

75.46 75.8

1 2 3 4 50 Month 1 month 3 Month 6 Month 12 Month

RESULTS

51

Graph 3: Mean ISQ values of Resorbable blast medium (RBM) treated surface (Group B)

Graph 4 : Change in ISQ over 1 year period for Resorbable blast medium

(RBM) treated surface (Group B)

70.66

55.55

69.56

76.83 77.56


70.66

55.55

69.56 76.83 77.56


RESULTS

52

Graph 5 : Comparison of ISQ values of Al Oxide blasted / acid etched surface (Group A)

and Resorbable blast medium (RBM) treated surface (Group B) implants at

different time intervals.

0

10

20

30

40

50

60

70

80

90

1 2 3 4 5

Series1

Series2

0 Month 1 month 3 Month 6 Month 12 Month

Group A

Group B

Discussion

DISCUSSION

53

The search for fixed functional and esthetic replacements for

missing natural teeth led to the introduction and subsequent widespread use of dental implants.

Continued research and innovation in implant biomaterials, macro and micro design , surgical

technique and prosthetic options have revolutionalised the field of implant dentistry . Of these ,

surface modification of endosteal implants received great attention among many

researchers1,7,33,44. Attempts to modify implant surfaces were aimed at achieving better

integration at cellular level , obtaining good primary stability , shortening treatment time etc.The

above mentioned aspects have been studied by many authors by employing invitro , histological

and clinical models .Many commercial dental implant manufacturers have developed and

patented unique surface treatments and claim superior results . However the validity of the claim

has to be verified by scientific means . Most of the studies regarding implant surface treatments

and their role in achieving and maintaining implant stability have been carried out in either

animal models or artificial bone models .Prospective controlled human clinical trials on implant

surface treatments are few and limited.

With this background , the present clinical study was done to

evaluate the primary and secondary implant stabilities of two different surface treated implants

and to compare the difference in stabilities of these two groups of implants . The present study

was designed to be a prospective controlled clinical trial employing a split mouth design .Split

mouth designs have many advantages over other clinical study protocols such as elimination of

intra subject bias , standardization of host environment , easy distribution of test samples etc

4.The completely edentulous mandibular arch was chosen for implant placement in this study.

This is because the bone quality in the mandible is predominantly of D1 and D2 types 4,16. Hence

standardization of surgical procedure for implant placement is better and there is hardly any need

DISCUSSION

54

to improve the bone quality by use of condensing osteotomes as is the case with edentulous

maxilla many a times .Also retention can be poor for mandibular complete denture when

compare with maxillary because of the anatomy , pattern of resorption , tongue position and

movement and attachment of muscles. Hence the need to improve the retention of mandibular

complete denture is more pronounced and this can be achieved either by means of removable

overdentures or fully fixed hybrid dentures. Accordingly the subjects in this study were

prescribed a mandibular full arch fixed prosthesis supported by six axially placed root form

endosteal implants opposing a conventional removable maxillary complete denture .

The study was triple blinded – the subject , the surgeon(operator)

and the investigator were blinded so as to eliminate bias at all levels. Since all the implants

placed in this study have the same macro design and there is no visible difference in their

surfaces clinically, the operator cannot identify the group to which the implant belongs to

.Furthermore, the surgical technique is the same for the placement of both the groups of

implants. Investigator bias is eliminated by identifying the implants based on their sites of

placement only. The values are then assigned to the particular sample and group by the

independent research assistant.

Immediate loading of all the implants was done with a metal

reinforced acrylic hybrid prosthesis inserted within a week of implant placement in accordance

to the ITI guide lines .(ITI consenus statement on loading protocols - 2012) . An implant level

screw retained , milled titanium frame work was fabricated since all the implants were axially

placed.

DISCUSSION

55

Primary stability of implants were measured and expressed in two

ways : i) insertion torque value ITV and ii) implant stability quotient(ISQ). The ITVs for

Group A - Al Oxide blasted / acid etched surface (Touareg S) (n=15) and Group B -

Resorbable blast medium (RBM) (Calcium phosphate) treated surface (Touareg OS) (n=15)

were compared using Mann – whitney test for non parametric data and there was no statistically

significant difference between the two groups ( p = 0.34). All the implants achieved an ITV of

>35 N cm , thus fulfilling the inclusion criteria and criteria for immediate functional loading.

The mean ISQ at the time of implant placement for Group A - Al Oxide blasted / acid etched

surface (Touareg S) was found to be 68.267 and that of Group B - Resorbable blast medium

(RBM) (Calcium phosphate) treated surface (Touareg OS) was found to be 70.667. There was

no statistically significant difference between the ISQ s of two groups immediately after

placement ( primary stability) ( p = 0.54). The lack of difference in primary stabilities of the two

groups can be attributed to the fact that both the groups of implants have similar sizes, geometry

and macro design.This finding is in accordance with previous studies such as the one by

Torroella et al where RFA was not able to detect major differences in implant primary stability

between the two implant designs24. Primary implant stability has been proven to be a mechanical

phenomenon .On the other hand , Secondary stability occurs through a cascade of biologic evens

sucha s bone regeneration and remodeling at the bone implant interface.

Another study by Alessandiopozi et al in 2014 affirmed that RFA

measurements present false positive results because it cannot detect the bone – implant contact at

deeper parts2. So it can happen that an implant inserted in a thin cortical bone but with high

density bone at the apical part had acceptable ITV but low ISQ values. However Bischof et al in

2004 found that the diameter does not affect the ISQ values13.

DISCUSSION

56

Primary stability is primarily important for implant

osseointegration. The lack of primary stability has openly been assumed to be the cause factor

for the early implant failure. ( Esposito et al 1998)18. Achieving stability depends on the bone

quality , surgical technique and the micro and macro design of the implant used . Thus implant

stability is the key to clinical success (Gapski et al 2013) 23.Optimal implant stabilization is

especially essential for immediate loading. It is known that implant primary stability depends on

the bone quality , surgical technique and implant design. Implant design plays an important role

in primary intra osseous stabilization. The wide diameter and long implants are recommended in

cases of poor bone density situations.26,40

In the present study , there was a statistically significant difference

among the implant stability quotient (ISQ) values of Al Oxide blasted / acid etched surface

(Group A) at different time intervals (p = 0.000). The same was noted in case of implant stability

quotient (ISQ) of Resorbable blast medium (RBM) treated (Group B) at different time intervals

(p =0.000). The increase in ISQ values over a one year period can be attributed to the fact that

improved osseointegration at the cellular level led to enhanced bone – implant contact (BIC)

which inturn increased the stability and stiffness of the implant – bone complex. However a

decrease in the ISQ values of both the group of implants were noted at a period of 1 month post

operatively. Earlier investigations showed that during the healing process, mechanical anchorage

of the implant in bone weakens. Conversely , biologic stability of the implant increases. This is

in concurrence with many of the previous studies.32,35,38,40

A few groups of authors have indicated that changes in stability

during healing were mainly dependant on the initial stability level of an implant. In their 12 week

DISCUSSION

57

clinical study, Nedir et al found that ITI implants with a pISQ les thsn 60 exhibites an increase in

stability whereas implant with apISQ of 60 -69 exhibited decrease stability ater 8 weeks13. At the

end of 12 weeks , the implants had returned to their initial stability values. Implants with pISQ

values greater than 69 exhibited decreased stability during the first 4 weeks after which they

maintained consistent stability. Similarly in 1999 Friberg et al stated that the stability of implants

placed in softer bone would catch up over time to implants placed in denser bone21. Balshi et al

and Olsson et al came to the conclusion that implants with high primary stability lost part of their

stability during healing whereas implants with low primary stability have a tendency to increase

their stability.6

Meredith 1996 et al and Friberg et al 1999 has also proposed that

the initial implant stability decreases as a result of bone compression caused by mechanical bone

relaxation, biological change during the primary bone recovery stage and initiation of marginal

bone resorption34,21. Glauser et al in 2001 performed RFA for 6 months after implantation of Ti

unite and machined surface which showed a decreasing pattern for first 3 weeks and then an

increasing pattern thereafter25.

Antonin Simuneck et al reported that a significant increase in

stability was recorded for the implants with low primary stability (PISQ<68), whereas the

implant with high primary stability (PISQ >72) lost some of the stability over time. On the basis

of linear regression analysis , the change in ISQ attains a value of zero at a primary ISQ of

69.2.40 Typically implant stability is anticipated to decrease during the early weeks of healing.

This is followed by an increase in stability .This is related to the biologic reaction of the bone to

surgical trauma. During the initial bone remodeling phase , bone and necrotic material are

resorbed by osteoclatic activity .It is reflected by a reduction in the ISQ value. This process is

DISCUSSION

58

followed by new bone apposition initated by osteobalastic activity i.e adaptive bone remodeling

around the implant .There is a lack of agreement among investigators regarding the exact timing

of greatest decrease in post insertion stability of an implant. The recorded data range between the

3 rd and 8th weeks following implant placement.37,39,40.41

Several factors may explain the drop of the ISQ during the first 3 –

6 months. The lateral compression exerted by the tapered implant on the osteotomy walls which

allows high primary stability may produce micro fracture of the cortial bone or elastic adaptation

of the trabecular bone which may result in the decrease of the ISQ. The remodeling process of

bone resorption and bone deposition that takes place during the early phase of osseo integration

may reduce the stiffness of the implant bone system. Conversely , the mineralization that occurs

on the cortical bone as a part of the healing reaction to surgical wounding and bone maturation

around the implants explain the increase in ISQ values from the 3 or 6 months to 12 months.

ISQ variation over a 1 year period as observed in the present

investigation seems to match the timing of bone formation and maturation described by Roberts.

According to Roberts, in Humans, the initial bone resorption and formation last about 4 months

and 8 more months are necessary for complete bone maturation. The absolute RFA values are

not completely dependant on the quality of osseointegration .There are three important factors

that can directly influence RFA : i) the stiffness of the implant bone interface ii) stiffness of the

bone itself and iii) stiffness of the implant components. Consequently , the clinically measurable

characterisitic of implant stability can be compared in the follow up of each individual implant.

But caution should be exerted in comparing these values among different implants , either in the

same patient or inter individually.

DISCUSSION

59

Another important observation in the present study is that there is

no statistically significant difference between the implant stability quotient (ISQ) values of Al

Oxide blasted / acid etched surface (Group A) and Resorbable blast medium (RBM) treated

(Group B) at different time intervals .( p value ranging from 0.4 to 0.7). This implies that both

the surface treatments researched in this study have the same effect on longterm implant

stability. Similar results are obtained by Sun – Jong Kim et al in his study who concluded that

the three groups ( machined ,SLA and anodized) did not show any significant difference in

primary stability in experimental dogs41. Schincaglia et al concluded that there is no difference

in ISQ values of machined and TiO surface coated implants over a period of one year 38. Similar

results were obtained by Karen fung et al over a 3 year split mouth clinical study on anodized

and machined titanium implant surfaces22. However Jan Gottolow et al in his animal study

concluded that SLA surfaces had more bone – implant contact and showed high removal torque

values than Oxidised surfaces after 6 weeks of healing29. Jeffcoat et al found hydroxyapatite

coated threaded implants to be more successful than HA coated cylinders and machined titanium

implants over a period of 5 years clinically. 33

In the present study, the surfaces tested were Al Oxide blasted /

acid etched surface (Group A) and Resorbable blast medium (RBM) (Calcium phosphate treated

surface) treated (Group B) . Both the surfaces showed similar primary and long term stability

over a period of one year. SLA surfaces have been extensively studied and proven to be effective

in enhancing implant stability when compared with machined and oxidized surfaces. SLA

treatment – a combination of blasting and acid treatment is performed by sandblasting the

implant with 25 – 50 µm Al2O3 particles and then etching with HCl / H2SO4 mixed solution .

Esposito et al observed an increase in alkaline phosphaase activity, DNA absorption in 3H

DISCUSSION

60

chimicin’s and collagenase by biochemically testing the condition of cultured cells in the SLA

treated titanium phase.18,19 Ganeles et al in 2008 reportd that even in poor bone quality , SLA

active surface were safe and predictable when used in immediate and early loading procedures.

The survival rate was comparable with that of conventional loading. In SLA treated implants ,

there was a significant difference in bone density between cancellous and compact bone. This

result suggests that there is a significant difference in bone response according to bone quality in

textured surface.

Implants with rough surfaces show a high success rate and an

excellent clinical outcome when used in poor quality bone. Wennerberg et al stated that the bone

to implat contact ration was higher in titanium implants with surface roughness of about 1.4 µm

than in smoother implants ( Sa =0.7 – 1.2 µm) or rougher implants (2.2 µm).47

However the concerns regarding the leaching of elemental Al ions

in the peri implant bone tissue in case of SLA treated implants led to other surface treatments

with biocompatible materials like Hydroxyapatite and calciumphosphate. Calcium phosphate is

used as the resorbable blast medium in the test group. It is claimed that RBM treated surfaces

are osteoconductive and there is an increase in Ca ion concentration in the peri implant host

tissue leading to improved osteogenesis , bone maturation and differentiation.RBM treatment

creates an extremely clean implant surface that does not inhibit gathering of osteoblast precursor

cells. This can however be verified only at the cellular level. As far as clinical implant stability is

concerned , both groups of implants with different surface treatments showed similar results

which were clinically acceptable. All the implants were successfully integrated as revealed by

the ISQ values and function well to support the prosthesis. Evaluation of other parameters like

peri implant soft tissue health , radiographic bone levels, patient perception etc., might reveal

DISCUSSION

61

differences if any among these two groups of implants and the clinician can make his choice

based on those factors given the fact that both types of implant achieve good primary and

longtem stability. Future research in this direction including assessment of peri implant soft

tissue health , microflora and histomorphometric analysis is warranted .

Summary and

Conclusion

SUMMARY

62

The present clinical study was conducted to determine the

difference in the primary and progressive stability if any, between two types of root form

endosseous implants with two distinct implant surfaces namely Acid etched surface/ Al Oxide

blasted surface and Restorable blast media (RBM) (Calcium phosphate ) treated surface when

loaded immediately with a full arch fixed prosthesis. The study was designed to be a split mouth

prospective clinical trial in which each patient received both the types of implants investigated

in either of the two quadrants of the mandible. The null hypothesis was that there is no

difference in the clinical stability of the two implant surfaces over a period of one year. A total

of 5 Completely edentulous patients who fulfilled the inclusion and exclusion criteria were

selected and written consent was obtained. A total of 30 implants ( n = 15 for each group) were

placed. The Alumina oxide blasted / acid etched surface (TOUAREG-S) is taken as the control

(Group A) and the Resorbable blast media (RBM) surface (TOUAREG-OS) is taken as the test

group(Group B) . All the implants were functionally loaded immediately with a fixed screw

retained hybrid denture opposing the maxillary conventional complete denture.

The clinical implant stability of all the 30 implants were measured individually at

different intervals - at the time of insertion, 1 month, 3 months, 6 months & 12 months after

insertion. The primary implant stability was measured using the calibrated torque wrench

(Insertion torque Value – ITV) and Resonance frequency Analysis (RFA). The progressive

stability at different time intervals were measured using RFA and the Implant Stability Quotient

(ISQ) values are recorded. The results were tabulated and subjected to statistical analysis.

The findings of the present study show that the insertion torque values (ITV) for

both Al Oxide blasted / acid etched surface(group A) and Resorbable blast medium (RBM) (

Calcium phosphate) treated surface (group B) were found to be in the range of >35 to >70 Ncm.

SUMMARY

63

The mean Implant Stability Quotient (ISQ ) value for Al Oxide blasted / acid etched

surface(group A ) was found to be 68.27, 54.26, 69.80 , 75.47 and 75.80 respectively and that of

Resorbable blast medium (RBM) ( Calcium phosphate) treated surface (group B) was found to

be 70.67, 55.50 69.56 76.83 and 77.5 respectively when measured at the time of insertion, 1

month, 3 months, 6 months & 12 months after insertion. There is a statistically significant

difference in stability for both the groups when compared individually among themselves over a

period of one year (p = 0.000) and there is no statistically significant difference in stability

between Al Oxide blasted / acid etched surface implants(group A) and Resorbable blast

medium (RBM) ( Calcium phosphate) treated surface (group B) at different time intervals - at

the time of insertion, 1 month, 3 months, 6 months & 12 months after insertion. (p =0.54 , 0.41,

0.96, 0.67 and 0.59 respectively).

Conclusion

CONCLUSION

63

The following conclusions were drawn from the present

clinical study conducted for the comparative evaluation of primary and progressive

stability of two different types of implants with different surface treatments namely i) Al

Oxide blasted / acid etched surface & ii) Resorbable blast medium (RBM) ( Calcium

phosphate) treated surface loaded immediately with a fixed full arch prosthesis.

1. The insertion torque values (ITV) for both Al Oxide blasted / acid etched

surface(group A) and Resorbable blast medium (RBM) ( Calcium phosphate)

treated surface (group B) were found to be in the range of >35 to >70 Ncm.

2. The mean Implant Stability Quotient (ISQ ) value for Al Oxide blasted / acid

etched surface(group A ) was found to be 68.27 and that of Resorbable blast

medium (RBM) ( Calcium phosphate) treated surface (group B) was found to be

70.67 immediately after placement (primary stability).




55.50 at one month after placement .




69.56 at three months after placement.

CONCLUSION

64




76.83 at six months after placement.




77.5 at twelve months after placement.

7. There is a statistically significant difference in stability among the Al Oxide

blasted / acid etched surface implants(group A) at different time intervals - at the

time of insertion, 1 month, 3 months, 6 months & 12 months after insertion. (p

=0.000).

8. There is a statistically significant difference in stability among the Resorbable

blast medium (RBM) ( Calcium phosphate) treated surface (group B) at different

time intervals - at the time of insertion, 1 month, 3 months, 6 months & 12

months after insertion. (p =0.000).

9. There is no statistically significant difference in stability between Al Oxide

blasted / acid etched surface implants(group A) and Resorbable blast medium

(RBM) ( Calcium phosphate) treated surface (group B) at different time intervals

- at the time of insertion, 1 month, 3 months, 6 months & 12 months after

insertion. (p =0.54 , 0.41, 0.96, 0.67 and 0.59 respectively).

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Abstract

Background :

Implant surface treatments influence the primary and longterm clinical stability of implants and their

loading protocols. Numerous in vitro and animal studies have researched the influence of surface

treatments on osseointegration at histological level. However Prospective clinical trials to study this

aspect are relatively few. Hence, the present clinical study was conducted to determine the difference in

the primary and progressive stability if any, between two types of root form endosseous implants with

two distinct implant surfaces.

Materials and method :

Two different implant surfaces namely Acid etched surface/ Al Oxide blasted surface (Group A) and

Resorbable blast medium (RBM) (Calcium phosphate) (Group B) treated surface were compared after

loading immediately with a full arch fixed prosthesis. Five completely edentulous patients received a

total of 30 implants (n =15 for each group) in the mandible and rehabilitated immediately with a fixed

screw retained hybrid denture. The clinical implant stability of all the 30 implants were measured

individually at different time intervals - at the time of insertion, 1 month, 3 months, 6 months & 12

months after insertion. The primary implant stability was measured using the calibrated torque wrench

(Insertion torque Value – ITV) and Resonance frequency Analysis (RFA). The progressive stability at

different time intervals were measured using RFA and the Implant Stability Quotient (ISQ) values are

recorded. The results were tabulated and subjected to statistical analysis.

Results :

The findings of the present study show that the insertion torque values (ITV) for both Al Oxide blasted /

acid etched surface(group A) and Resorbable blast medium (RBM) ( Calcium phosphate) treated surface

(group B) were found to be in the range of >35 to >70 Ncm. The mean Implant Stability Quotient (ISQ )

value for Al Oxide blasted / acid etched surface (group A ) was found to be 68.27, 54.26, 69.80 , 75.47

and 75.80 respectively and that of Resorbable blast medium (RBM) ( Calcium phosphate) treated surface

(group B) was found to be 70.67, 55.50, 69.56, 76.83 and 77.5 respectively when measured at the time of

insertion, 1 month, 3 months, 6 months & 12 months after insertion. There is a statistically significant

difference in stability for both the groups when compared individually among themselves over a period of

one year (p = 0.000) and there is no statistically significant difference in stability between Al Oxide

blasted / acid etched surface implants(group A) and Resorbable blast medium (RBM) ( Calcium

phosphate) treated surface (group B) at different time intervals - at the time of insertion, 1 month, 3

months, 6 months & 12 months after insertion. (p =0.54 ,0.41,0.96,0.67 and 0.59 respectively).

Conclusion :

Within the limitations of this study , there is no statistically significant difference in stability

between Al Oxide blasted / acid etched surface implants and Resorbable blast medium treated surface at

different time intervals. However, there is a statistically significant increase in stability over time for both

the groups of implants when assessed individually.

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